1. Field of the Invention
The present invention relates to a semiconductor storage device that is capable of reading data stored in memory elements.
2. Description of the Related Art
Conventionally, as storage devices using semiconductor elements, DRAMs (dynamic random access memories), which have a simple structure but require refreshing, and FeRAMs (ferroelectric random access memories), which include a ferroelectric material and which can be used as nonvolatile memories, have been used.
Moreover, in recent years, semiconductor storage devices, such as MRAMs (magnetic random access memories) that store data according to whether a resistance is large or small, are under intense development.
An example of such a technology is proposed in Non-patent Document 1, “Soshite-subeteno-memori-wa-fukihatsusei-ni-naru (Every memory then becomes nonvolatile)”, “Nikkei Electronics”, Feb. 12, 2001, No. 789, Nikkei Business Publications Inc., pp.151–177.
With the MRAMs, however, when memory elements are configured with only resistors typified by TMR (tunneling magneto resistive) elements, there is a problem in that it is difficult to detect data due to leakage current. As a result, resistors and transistors must be combined to constitute the memory elements.